// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/ftp/ftp_directory_listing_parser.h"

#include "base/bind.h"
#include "base/callback.h"
#include "base/i18n/icu_encoding_detection.h"
#include "base/i18n/icu_string_conversions.h"
#include "base/stl_util.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "net/base/net_errors.h"
#include "net/ftp/ftp_directory_listing_parser_ls.h"
#include "net/ftp/ftp_directory_listing_parser_vms.h"
#include "net/ftp/ftp_directory_listing_parser_windows.h"
#include "net/ftp/ftp_server_type_histograms.h"

namespace net {

namespace {

    // Fills in |raw_name| for all |entries| using |encoding|. Returns network
    // error code.
    int FillInRawName(const std::string& encoding,
        std::vector<FtpDirectoryListingEntry>* entries)
    {
        for (size_t i = 0; i < entries->size(); i++) {
            if (!base::UTF16ToCodepage(entries->at(i).name, encoding.c_str(),
                    base::OnStringConversionError::FAIL,
                    &entries->at(i).raw_name)) {
                return ERR_ENCODING_CONVERSION_FAILED;
            }
        }

        return OK;
    }

    // Parses |text| as an FTP directory listing. Fills in |entries|
    // and |server_type| and returns network error code.
    int ParseListing(const base::string16& text,
        const base::string16& newline_separator,
        const std::string& encoding,
        const base::Time& current_time,
        std::vector<FtpDirectoryListingEntry>* entries,
        FtpServerType* server_type)
    {
        std::vector<base::string16> lines;
        base::SplitStringUsingSubstr(text, newline_separator, &lines);

        struct {
            base::Callback<bool(void)> callback;
            FtpServerType server_type;
        } parsers[] = {
            { base::Bind(&ParseFtpDirectoryListingLs, lines, current_time, entries),
                SERVER_LS },
            { base::Bind(&ParseFtpDirectoryListingWindows, lines, entries),
                SERVER_WINDOWS },
            { base::Bind(&ParseFtpDirectoryListingVms, lines, entries),
                SERVER_VMS },
        };

        for (size_t i = 0; i < arraysize(parsers); i++) {
            entries->clear();
            if (parsers[i].callback.Run()) {
                *server_type = parsers[i].server_type;
                return FillInRawName(encoding, entries);
            }
        }

        entries->clear();
        return ERR_UNRECOGNIZED_FTP_DIRECTORY_LISTING_FORMAT;
    }

    // Detects encoding of |text| and parses it as an FTP directory listing.
    // Fills in |entries| and |server_type| and returns network error code.
    int DecodeAndParse(const std::string& text,
        const base::Time& current_time,
        std::vector<FtpDirectoryListingEntry>* entries,
        FtpServerType* server_type)
    {
        const char* const kNewlineSeparators[] = { "\n", "\r\n" };

        std::vector<std::string> encodings;
        if (!base::DetectAllEncodings(text, &encodings))
            return ERR_ENCODING_DETECTION_FAILED;

        // Use first encoding that can be used to decode the text.
        for (size_t i = 0; i < encodings.size(); i++) {
            base::string16 converted_text;
            if (base::CodepageToUTF16(text,
                    encodings[i].c_str(),
                    base::OnStringConversionError::FAIL,
                    &converted_text)) {
                for (size_t j = 0; j < arraysize(kNewlineSeparators); j++) {
                    int rv = ParseListing(converted_text,
                        base::ASCIIToUTF16(kNewlineSeparators[j]),
                        encodings[i],
                        current_time,
                        entries,
                        server_type);
                    if (rv == OK)
                        return rv;
                }
            }
        }

        entries->clear();
        *server_type = SERVER_UNKNOWN;
        return ERR_UNRECOGNIZED_FTP_DIRECTORY_LISTING_FORMAT;
    }

} // namespace

FtpDirectoryListingEntry::FtpDirectoryListingEntry()
    : type(UNKNOWN)
    , size(-1)
{
}

int ParseFtpDirectoryListing(const std::string& text,
    const base::Time& current_time,
    std::vector<FtpDirectoryListingEntry>* entries)
{
    FtpServerType server_type = SERVER_UNKNOWN;
    int rv = DecodeAndParse(text, current_time, entries, &server_type);
    UpdateFtpServerTypeHistograms(server_type);
    return rv;
}

} // namespace net
